Definition of cult
1 : a religion regarded as unorthodox or spurious - also : its body of adherents
2 a : great devotion to a person, idea, object, movement, or work (such as a film or book)
b : the object of such devotion
c : a usually small group of people characterized by such devotion the singer's cult of fans The film has a cult following.
3 : a system of religious beliefs and ritual; also : its body of adherents the cult of Apollo
4 : formal religious veneration : worship
5 : a system for the cure of disease based on dogma set forth by its promulgator health cults

christianity fits all 5.

1. tens of thousands of children raped in its churches. pretty goddam unorthodox!
2. obvious
3. obvious
4. obvious
5. many of the morons think praying will heal them.

And, you only need ONE of the above for it to be a proper usage of the term.

For example, christianity started as a cult in Rome and was heavily persecuted. After it rose to power, it became a "religion" and all of the prior pagan religions became the "cults" when christians persecuted them instead.

“Cult” is a word that is too ambiguous to have any specific meaning. It is used mostly as a put-down for any group that is despised by another.

Wikipedia:
The term cult usually refers to a social group defined by its religious, spiritual, or philosophical beliefs, or its common interest in a particular personality, object or goal. The term itself is controversial and it has divergent definitions in both popular culture and academia and it also has been an ongoing source of contention among scholars across several fields of study.

In today's usual use of the word 'cult' it is a group in which a person or set of persons has functionally become god to the followers.
Those same people holding power over the followers "acceptability".

Not all cults are religious. Some are business - usually multi-level marketing schemes with a pyramid structure.

Classically a 'cult' is any sort of structured religion ... but that is not how the word is used these days.

Definitions of cult and religion are rather broad. It depends on what a person means by cult or religion; which definition they are depending on to describe them. Cult these says is used negatively these days. Religion, I think, is used both negatively and positively.

I will give you a source with the long list given to the word Cult for an example. Apply them as you see fit.

Cult
noun
1.
a particular system of religious worship, especially with reference to its rites and ceremonies.
2.
an instance of great veneration of a person, ideal, or thing, especially as manifested by a body of admirers:
the physical fitness cult.
3.
the object of such devotion.
4.
a group or sect bound together by veneration of the same thing, person, ideal, etc.
5.
Sociology. a group having a sacred ideology and a set of rites centering around their sacred symbols.
6.
a religion or sect considered to be false, unorthodox, or extremist, with members often living outside of conventional society under the direction of a charismatic leader.
7.
the members of such a religion or sect.
8.
any system for treating human sickness that originated by a person usually claiming to have sole insight into the nature of disease, and that employs methods regarded as unorthodox or unscientific.
adjective
9.
of or relating to a cult.
10.
of, for, or attracting a small group of devotees:
a cult movie. http://www.dictionary.com/browse/cult

Religions spawn cults . The main values established eventually become abused and the religious leader eventually spins new more modern beliefs into a central religious belief .
Jim Jones and David Koresh were Christians until they turned Jesus into themselves as cult leaders .. S Basically it's when honor god turns into eat my shorts